Items of travel equipment in the sense of the present invention are escalators and moving walkways with a plurality of tread units connected with an endless conveyor. Users of the travel equipment stand on tread surfaces of the tread units or walk on the travel equipment in the same direction as the travel equipment themselves move.
In the case of escalators the tread units form escalator steps, termed ‘steps’ in the following, and in the case of moving walkways the tread units form moving walkway plates, termed ‘plates’ in the following. Escalators overcome, with a relatively large angle of inclination, large differences in height, such as entire storys. Moving walkways run horizontally or at a slight inclination, but generally with lower angles of inclination than escalators.
The tread units are, particularly in the case of poor weather, walked on by wet and dirty footwear. As a result, not only the tread surfaces of the tread units, but also laterally adjoining stationary parts of the travel equipment, are soiled. Additional sources of dirt are escaping or excessive lubricant by which certain parts of the travel equipment are lubricated, as well as abrasion materials of guide elements which run against one another during movement of the travel equipment. In order to keep the travel equipment functionally capable and safe and to increase its service life, as well as to avoid noise due to worn and contaminated parts of the travel equipment, it is therefore necessary to undertake sufficient cleaning measures.
Manual cleaning is not held in high regard by operators of travel equipment, since it is unpleasant and time consuming and has the consequence on each occasion of a very long interruption of operation.
Accordingly, cleaning systems have been developed by which it is sought to avoid these disadvantages.
JP-08157176-A describes a cleaning system for cleaning stationary parts of the travel equipment, which laterally adjoin the tread units. This system contains cleaning elements in the form of brush elements which are arranged below the tread surfaces in the lateral regions of a tread unit to be invisible for users and move together with the tread unit. The brush arrangements can for cleaning purposes, be temporarily adjusted laterally outwardly from rest positions to operative positions in which they wipe along the stationary regions of the travel equipment to be cleaned. The adjustment of the cleaning elements or brush arrangements takes place by remote control. It is regarded as an advantage of this cleaning system that the operation of the travel equipment does not have to be interrupted during the cleaning process. However, it is necessary from time to time to interrupt operation of the travel equipment in order to replace worn brush arrangements of the cleaning elements. The wear may be comparatively high, since the brush arrangements always wipe in the same direction along the surfaces to be cleaned. Moreover, the remote control for adjusting the cleaning elements or brush arrangements is relatively complicated and is disposed in the contaminated region of the travel equipment, and thus is susceptible to disturbance or damage.
US-2001/0025764-A1 discloses cleaning systems with cleaning elements in the form of cleaning modules or cleaning blocks, particularly of fibre-filled plastics materials, which during movement of the endless conveyor constantly scrape off or scrub off contaminants from soiled stationary surfaces. The cleaning elements can be provided with a so-termed cleaning medium, not a liquid or pasty cleaning agent, but a cover in the form of a brush structure. The cleaning elements are fastened laterally below a cleaning unit which, for cleaning purposes is mounted in place of guide elements. It is disadvantageous with this cleaning system in that the substantially rigid cleaning elements can leave scratch tracks at the surfaces to be cleaned and that the cleaning elements wear out quickly. This is the case, even if to a moderated degree, when the cleaning elements have a cleaning medium with a brush structure. Moreover, it has proved necessary to secondarily clean the cleaning elements themselves to a certain degree, for which purpose a brush arrangement can be provided. However, such thereby results in a comparatively complicated cleaning system.
It is therefore objects of the invention to create a cleaning unit of the kind stated in the introduction, by which the mentioned disadvantages are avoided and which cleans efficiently, is not susceptible to disturbance and has a high service life;                to provide travel equipment which can be cleaned by such a cleaning unit; and        to provide a method for carrying out a cleaning sequence for cleaning the travel equipment.        
According to the invention the foregoing and other objects and purposes are met by a cleaning unit for travel equipment, and particularly escalators and moving walkways, in the form of a unit that can be mounted in place of a tread unit for a cleaning cycle or process and then demounted from the travel equipment and the conclusion of the cycle or process.
By a cleaning unit there is to be understood within the scope of the present description a step or plate, which is constructed for cleaning the travel equipment, including all its individual components even when these do not form a “unit” in the actual sense of the word.
According to the invention the new cleaning unit is not a step or plate permanently mounted in the endless conveyor of the escalator or moving walkway, but it is mounted as a substitute for a usual step or plate only temporarily for a cleaning sequence with respect to cleaning purposes. In this connection small or short mounting and demounting operations (approximately 2 to 5 minutes expenditure of time) do indeed occur for each cleaning process, but this small disadvantage is offset by the advantages of the invention. The most important advantages of the invention are to be seen in that                a more efficient and complete cleaning can be undertaken by new cleaning units;        the cleaning unit is not susceptible to disturbance and has a long service life, since it is not permanently in use;        possible disturbances of the cleaning unit can be eliminated in a simple manner and worn cleaning elements can be replaced when the cleaning unit is not in use and is demounted, as a result a secondary cleaning of the cleaning elements during use is not needed;        a single cleaning unit can be used in connection with a number of travel equipment units;        cleaning of stationary lateral walls, even in the visible region thereof can be accomplished, whereas with the previously known cleaning units in the case of escalators only a visible strip, narrow in height, could be cleaned and, moving walkways, no visible parts at all could be cleaned;        depending on the respective degree or kind of contamination, specifically acting cleaning units can be installed, which are suitable for, for example, removing dry dust or dirt containing lubricant or slush containing dispersed salt, wherein optionally a specifically acting cleaning agent or neutralisation agent, preferably in fluid form, can be added;        in the case of need further tread units can be temporarily replaced by cleaning units;        demounting of tread units, in a given case to clean, check or replacement can be accomplished; and        cleaning performed in a cleaning mode of operation of the travel equipment allows the endless conveyor to be so moved that the cleaning is performed in an optimum manner, wherein the endless conveyor can be moved in a different manner with respect to speed and direction than in a normal operating mode.        
Preferably the cleaning elements are constructed as brush arrangements which are arranged in side regions of a cleaning step unit in such a manner that during the cleaning process they project slightly beyond the lateral boundaries of the step units and contact the adjoining stationary walls in a cleaning manner. The cleaning elements can also be constructed as a sponge or a cloth. A washing train can also be formed: sponge, brush, cloth and drier. Cleaning elements in the form of brushes are subject to only slight wear. With suitable selection of the bristle material, bristle dimensions and pressing pressure, scratch tracks on the cleaned surfaces can be avoided and, in fact, will not result due either to the bristles themselves or due to foreign particles, since such are only lightly pressed against the surfaces or wiped along the surfaces by the brushes of the brush arrangements. Moreover, due to the resilient flexibility of the bristles it is not necessary to position the brushes with a high degree of accuracy.
Use may be made of brush arrangements with brushes which lie below a surface which corresponds to the tread surface of the tread units of the cleaning unit. The travel equipment can thereby in a given case also be used by the public while the cleaning unit is installed.
In order to also clean considerable visible regions of the stationary lateral walls of the travel equipment there can be used a brush arrangement which has brushes which lie above a surface which corresponds with the tread surface of the tread units of the cleaning unit. In this connection, however, the travel equipment should no longer be made available to the public without restriction, but it is still possible for operators to be able to stand on the surface.
A respective brush arrangement may be provided at both side regions of the cleaning step, and it has proved advantageous if each of the brush arrangements comprises at least one non-rotatably mounted brush and at least one rotatably mounted brush. The non-rotatably mounted brush can either be fixedly mounted or mounted for area vibration. The rotatably mounted brush, which is also termed a “roller brush”, is generally set in rotation by a movement produced in the travel direction of the cleaning step. The two brushes are preferably detachably mounted, for example by means of bolt/nut connections.
The non-rotatably mounted brush can be fastened to a support body of the cleaning unit which in turn is mounted to a body of the cleaning unit, preferably detachably and by means of, for example, a further bolt/nut connection. The rotatably mounted brush, which can be constructed as a roller brush, is fastened to a roller shaft of the cleaning unit by means of, for example, a screw or bolt connection.
It is particularly favourable if a flowable cleaning agent, preferably a fluid, is fed to at least a part of the brushes continuously or at intervals in time. In this connection the flowable cleaning agent can be fed from a cleaning agent dispenser which co-moves solidly with the cleaning step. The feed of the cleaning agent is advantageously carried out automatically or by gravitational force. The fluid dispenser can be, depending on the respective arrangement of the brushes, a gravity dispenser or a pump dispenser, wherein the pump can have an approximate form of drive. It can be driven, for example, electrically, mechanically or chemically by combustion cells or by compressed air.
Travel equipment in the form of an escalator or moving walkway, with tread units which are connected to an endless conveyor, are usually disposed in an operating mode in which the endless conveyor is driven. For carrying out a cleaning sequence in accordance with the invention, the travel equipment is shifted to a cleaning mode, wherein the endless conveyor is stopped, at least one tread unit is replaced by at least one cleaning unit, the endless conveyor is driven again for the actual cleaning and subsequently the cleaning units are demounted and tread units remounted. The travel equipment can thereupon be shifted back to its operating mode.